Abstract
The glass-ionomer cements have many advantages such as release of fluoride for caries resistance, biocompatibility, esthetics, and sufficient teeth adhesion. The purpose of this study was to determine if short fibers of CaO-P2O5-SiO2-Al2O3 (CPSA) short glass fiber (diameter,9.7±2.1μm; aspect ratio,5.0±0.9)could be effective as a reinforcing agent for glass-ionomer cement. A commercially available glass-ionomer cement (HY-BOND GLASIONOMER CX; Shofu Inc., Kyoto, Japan)was used in this study. The powder for the cement was prepared by mixing the powder of the glassionomer cement and CPSA short glass fibers. The contents of CPSA short fibers in the mixed powder were 0,20 and 50 wt%. The powder was mixed with a commercial liquid at a powder/liquid ratio of 1.46, according to the manufacturer's instructions. After mixing, the cement pastes were placed in a glass split mold. The specimens were kept in an incubator at a temperature of 37°C and relative humidity of approximately 100%. After 24 hours of storage, micro-tensile strength and flexural strength of the set cements were evaluated. The strengths of glass-ionomer cements containing 50 wt% short fibers were approximately two times larger than those non-containing short fibers. The scanning electron micrograph observation showed that the set cements dispersed with glass fibers were strengthened by bonding between the cement matrix and the short fibers. The CPSA glass short fibers played an important role as a reinforcing agent for strengthening the glass-ionomer cement due to the shape of the short fibers and the chemical reactivity between the mixing liquid (or cement matrix) and short fibers. The glass ionomer cement strengthened by glass short fiber is promising as a new dental material.
